Material or curable solvent-based topcoating material, and coating material and coating film comprising or formed from the same

ABSTRACT

To provide a coating material for a curable solvent-based topcoating material, having excellent marring resistance, chipping resistance, producing no crack and excellent in performances such as weatherability, stain resistance, adhesion and the like, and a curable solvent-type topcoating material using such a material. 
     A coating material is blended preferably in an amount of 60 to 90% by mass relative to paint film forming components thereby to form a curable solvent-based topcoating material. The coating material includes an oleophilic polyrotaxane which includes a cyclic molecule, a linear molecule including the cyclic molecule with piercing through the cyclic molecule, and blocking groups which are placed at both end terminals of the linear molecule to prevent the cyclic molecule from leaving from the linear molecule, at least one of the above-mentioned liner molecule and the cyclic molecule having hydrophobic modification group.

This application is a divisional application of U.S. application Ser.No. 12/089,329, filed Apr. 4, 2008, which is the National Stageapplication of International Application No. PCT/JP2006/319966, filedOct. 5, 2006, which claims the priority to Japan Application Nos.2005-293830 and 2005-293831, both filed Oct. 6, 2005. All of which arehereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates to a curable solvent-based topcoating material,and a coating material and coating film using this, and morespecifically a material for the curable solvent-based topcoatingmaterial, applicable particularly to products to be used in fieldsrequiring marring resistance, such as mainly an automotive vehicle body;resinous formed articles in inside and outside of house; wood productssuch as stairs, floor, furniture and the like; an aluminum wheel, a doormirror or the like which are treated by plating, vapor deposition,sputtering and the like, and the coating material and coating film usingthis.

2. Background Art

Hitherto, a resinous formed article such as a polycarbonate plate or anacrylic plate are inferior in various physical properties such ashardness, weatherability, stain resistance, solvent resistance and thelike, and therefore a surface treatment is applied in order tocompensate these physical properties.

For such a surface treatment, for example, a curable paint such as anambient temperature drying paint or a two package type urethane resinpaint are used (see, for example, Patent Literature 1)

However, a treatment film using the paint tends to be readily scratched,and formed scratches tend to be conspicuous.

Patent Literature 1: Japanese Patent Provisional Publication No.2004-131601

Additionally, for a design purpose, a metallic mirror treatment such asplating, vapor deposition, sputtering or the like is used (see, forexample, Patent Literature 2).

However, in case of carrying out the metallic mirror treatment, atreatment film tends to be readily scratched, and formed scratches tendto be conspicuous. Additionally, the surface treatment as mentionedabove is usually carried out after the mirror treatment such assputtering; however, an obtained treatment film tends to be readilyscratched, and formed scratches tend to be conspicuous.

Patent Literature Japanese Patent Provisional Publication No.2003-293146

Further, regarding a top coat for an automotive vehicle, ahigh-durability intention is recently being strengthened in order tomaintain a painted appearance at a new car time for a long period oftime. As a result, a marring resistance is being required to prevent acoated paint from being scratched even by a car washer, dust, flyingstone or the like.

As a paint having a marring resistance, hitherto an ultraviolet ray (UV)curable paint, an electron beam (EB) curable paint, a silica-based hardcoating agent, a two package type acrylic urethane-based soft paint orthe like is known (see, for example, Patent Literature 3).

Patent Literature 3: Japanese Patent Publication No. 6-29382

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

However, with the above-mentioned UV curable paint, EB curable paint orsilica-based hard coating agent, problems of lowering adhesion of thepaint to a material and of forming crack tend to readily arise underusing hard monomer for realizing a high hardness and an increase instrain during hardening and shrinkage owing to an increased crosslinkagedensity.

In this regard, the above-mentioned two package type acrylicurethane-based soft paint raises no problem of chipping and cracking;however, there many cases where tack feeling is left, so that the painthas a defect of being inferior in weatherability and stain resistance.

The present invention is made in view of such problems of conventionaltechniques, and an object of the present invention is to provide amaterial for a curable solvent-based topcoating material, havingexcellent marring resistance, chipping resistance and able to form apaint film difficult to form crack and the like, and coating materialand film using this.

Means for Solving Problems

As a result of repeating eager studies to attain the above-mentionedobject, the present inventors have found that the above-mentioned objectcan be attained and reached the completion of the present invention, byusing an oleophilic polyrotaxane whose linear molecule and cyclicmolecule are provided with hydrophilic modification groups.

In other words, a material for a curable solvent-based topcoatingmaterial, according to the present invention is characterized bycomprising an oleophilic polyrotaxane singly or both the polyrotaxaneand another resin, the oleophilic polyrotaxane including a cyclicmolecule, a linear molecule including the cyclic molecule with piercingthrough the cyclic molecule, and blocking groups which are placed atboth end terminals of the linear molecule to prevent the cyclic moleculefrom leaving from the linear molecule, the liner molecule and/or thecyclic molecule having a hydrophobic modification group. Examples of theanother resin are acrylic resin, epoxy resin, polyester resin and thelike; however, the another resin is not limited to these.

Additionally, a preferred embodiment of the material for a curablesolvent-based topcoating material, according to the present invention ischaracterized in that the cyclic molecule has an inclusion amountranging from 0.06 to 0.61 relative to 1 which is the maximum inclusionamount of the cyclic molecule capable of being included by the linearmolecule.

Further, another preferred embodiment of the material for a curablesolvent-based topcoating material, according to the present invention ischaracterized in that the linear molecule has a molecular weight rangingfrom 1,000 to 45,000.

Additionally, the curable solvent-based topcoating material according tothe present invention is characterized by using the material for acurable solvent-based topcoating material.

Further, the curable solvent-based topcoating paint film is formed bysolidifying the curable solvent-based topcoating material.

Furthermore, the laminated coating film according to the presentinvention uses the above-mentioned solvent-based topcoating material andformed by successively forming a base coat paint film and a clear paintfilm using the solvent-based topcoating material on an article to becoated; by successively forming a base coat paint film using thesolvent-based topcoating material and a clear paint film on an articleto be coated; or by forming an enamel paint film using the solvent-basedtopcoating material on an article to be coated.

EFFECTS OF THE INVENTION

According to the present invention, the oleophilic polyrotaxane whoselinear molecule and/or cyclic molecule are provided with hydrophobicmodification groups is used, thereby making it possible to provide thematerial for the curable solvent-based topcoating material, able to forma paint film having excellent marring resistance and difficult to formcrack and the like, and the coating material and coating film usingthis.

THE BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a material for a curable solvent-based topcoating material,according to the present invention will be discussed in detail. In thespecification of the present application, “%” represents % by massunless otherwise specified.

As discussed above, the material for a curable solvent-based topcoatingmaterial, according to the present invention includes single oleophilicpolyrotaxane, or both the polyrotaxane and other resin(s).

This oleophilic polyrotaxane includes a cyclic molecule, and a linearmolecule having blocking groups at its both end terminals. The linearmolecule includes the cyclic molecule with piercing through the openingsection of the cyclic molecule. Further, the blocking groups placed atboth end terminals of the linear molecule prevent the included cyclicmolecule from leaving from the linear molecule.

Furthermore, either one or both of the linear molecule and the cyclicmolecule constituting this polyrotaxane has hydrophobic modificationgroup(s).

FIG. 1 is a schematic illustration which conceptually shows theoleophilic modified polyrotaxane.

In the same figure, this hydrophobic modified polyrotaxane 5 has thelinear molecule 6, the cyclodextrin 7 as the cyclic molecule, and theblocking groups 8 placed at the both end terminals of the linearmolecule 6, in which the linear molecule 6 includes the cyclic molecule7 with piercing through the opening section of the cyclic molecule 7.

The cyclodextrin 7 has the hydrophobic modification groups 7 a.

By using such an oleophilic polyrotaxane, a material for a coatingmaterial miscible with a hydrophobic solvent can be obtained.Additionally, when it is applied to a coating material, the durabilityof a product can be improved. In other words, the coating material isimproved in marring resistance and chipping resistance effectivelybecause no baneful effect is applied to other required performances.Further, the coating material is excellent in weatherability, stainresistance, adhesion and the like.

Here, the above-mentioned linear molecule is sufficient to besubstantially linear and is sufficient to have a branched chain as faras it can include the cyclic molecule as a rotator in such a manner asto be rotatable to exhibit a pulley effect.

Additionally, the length of the linear molecule is not particularlylimited as far as the cyclic molecule can exhibit the pulley effect,though it is affected by the size of the cyclic molecule.

In the material for a curable solvent-based topcoating material,according to the present invention, either one or both of the linearmolecule and the cyclic molecule has the hydrophobic modification group,by which the material is soluble in an organic solvent.

Such exhibition of the oleophilic characteristic provides a reactionfield, typically the crosslinking field, of the organic solvent topolyrotaxane which is hitherto almost insoluble or insoluble in awater-like solvent or an organic solvent. In other words, the materialfor a curable solvent-based topcoating material, according to thepresent invention is improved in reactivity so that crosslinking withother polymers and modification with modification groups can be readilyaccomplished in presence of the organic solvent.

The above-mentioned modification group has the hydrophobic group or boththe hydrophobic group and the hydrophilic group, and is sufficient to behydrophobic as a whole.

Examples of such hydrophobic group are, for example, alkyl group, benzylgroup, benzene derivative-containing group, acyl group, silyl group,trityl group, tosyl group, urethane linkage, ester linkage, etherlinkage and the like; however, the hydrophobic group is not limited tothese.

Examples of such hydrophilic group are, for example, alkyl group,carboxyl group, sulphonic acid group, sulfuric ester group, phosphoricester group, primary to tertiary amino group, quaternary ammonium saltgroup, hydroxyalkyl group, and the like; however, the hydrophilic groupis not limited to these.

Such a linear molecule is not limited to a particular one, in which theexamples of the linear molecule are polyalkyls, polyesters such aspolycaprolactone, polyethers, polyamides, polyacrylics and a linearmolecule having benzene ring(s).

In concrete, examples of the linear molecule are polyethylene glycol,polyisoprene, polybutadiene, polypropylene glycol, polytetrahydrofuran,polydimethylsiloxane, polyethylene, polypropylene, and the like. As sucha linear molecule, polyethylene glycol and polycaprolactone areparticularly preferable.

Additionally, the molecular weight of the linear molecule is preferablywithin a range of from 1,000 to 45,000, more preferably within a rangeof from 10,000 to 40,000, furthermore preferably within a range of from20,000 to 35,000.

If the molecular weight is less than 1,000, the pulley effect isdegraded so that the elongation percentage of a coating film is lowered,thereby providing a possibility that marring resistance and chippingresistance are degraded. If the molecular weight exceeds 45,000, asolubility lowers, providing a possibility that an appearance such assmoothness or luster as enamel for film formation on a surface islowered.

The above-mentioned linear molecule preferably has reactive groups atits both end terminals, by which the linear molecule can be readilyreacted with the above-mentioned blocking groups.

Such reactive groups may be suitably changed in accordance with kinds ofthe blocking group to be used, in which examples of the reactive groupsare hydroxyl group, amino group, carboxyl group, thiol group and thelike.

Examples of the above-mentioned cyclic molecule are a variety of cyclicmaterials and not limited to particular ones as far as they produce thepulley effect by being included by the linear molecule as discussedabove. Many cyclic molecules have hydroxyl group(s).

Additionally, the cyclic molecule is sufficient to be substantiallycyclic and therefore includes a C-shaped one which does not form acompletely closed ring.

Additionally, the above-mentioned cyclic molecule preferably hasreactive groups, by which the linear molecule can be readily crosslinkedwith other polymers and combined with modification group(s).

Such reactive groups may be suitably changed, in which examples of thereactive groups are hydroxyl group, amino group, carboxyl group, thiolgroup, aldehyde group.

Additionally, the reactive groups are preferably reactive groups whichcannot react with the blocking groups when the blocking groups areformed (blocking reaction) as discussed after.

Further, concrete examples of the above-mentioned cyclic molecule are avariety of cyclodextrins, for example, α-cyclodextrin (the number ofglucose: 6), β-cyclodextrin (the number of glucose: 7), γ-cyclodextrin(the number of glucose: 8), dimethylcyclodextrin, glucocylcyclodextrinand derivatives and modified compounds of these, and crown ethers,benzocrowns, dibenzocrowns, dicyclohexanocrowns and derivatives andmodified compounds of these.

One kind of the above-mentioned cyclodextrins can be singly used, or notless than two kinds of them are used in combination.

Particularly, α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin arepreferable, in which α-cyclodextrin is preferable from the viewpoint ofthe characteristics of being included.

Additionally, if hydrophobic modification group(s) is introduced tohydroxyl group(s) of the cyclodextrin, the solubility of the oleophilicpolyrotaxane in a solvent can be further improved.

At this time, a modification degree of the cyclodextrin with theabove-mentioned hydrophobic modification groups is preferably not lessthan 0.02, more preferably not less than 0.04 and furthermore preferablynot less than 0.06 on the assumption that the maximum number ofmodifiable hydroxyl groups of the cyclodextrin is 1.

If it is less than 0.02, the solubility in the organic solvent isinsufficient so that insoluble seed (projection sections derived fromforeign matter adhesion and the like) may be produced.

Here, the maximum number of the modifiable hydroxyl groups of thecyclodextrin is, in other words, the number of all hydroxyl groups whichthe cyclodextrin have had before the modification. The modificationdegree is, in other words, a ratio of the number of the modifiedhydroxyl groups to the number of all hydroxyl groups.

The hydrophobic group is sufficient to be at least one, in which it ispreferable that each cyclodextrin ring has one hydrophobic group.

Additionally, by introducing the hydrophobic group having functionalgroup(s), it is possible to improve the reactivity of the polyrotaxanewith other polymers.

As an introduction method for the above-mentioned hydrophobicmodification group, the following method will be employed.

A first method is as follows: For example, a cyclodextrin is used as thecyclic molecule of the polyrotaxane, and hydroxylpropylation of hydroxylgroups of the cyclodextrin is carried out with propylene oxide.Thereafter, ε-caprolactone is added, and then tin 2-ethylhexanoate isadded. The modification rate can be freely controlled by changing theaddition amount of ε-caprolactone at this time.

In the material for a curable solvent-based topcoating material,according to the present invention, the number (an inclusion amount) ofthe cyclic molecules included by the linear molecule is preferablywithin a range of 0.06 to 0.61, more preferably within a range of from0.11 to 0.48, and furthermore preferably within a range of from 0.24 to0.41 on the assumption that the maximum inclusion amount is 1.

If the inclusion amount is less than 0.06, the pulley effect will bedegraded, and there is a possibility that the elongation percentage of acoating film is lowered. If the inclusion amount exceeds 0.61, thecyclic molecules are placed too close each other so that the moveabilityof the cyclic molecules may be lowered, which may lower the elongatepercentage, marring resistance and chipping resistance of the coatingfilm.

Additionally, the inclusion amount of the cyclic molecule can becontrolled as set forth below.

A first method is as follows: BOP reagent(benzotirazole-1-yl-oxy-tris(dimethylamino)phosphoniumhexafluorophosphate), HOBt, adamantane amine and diisopropylethyl amineare added in this order in DMF (dimethylformamide) thereby form asolution. On the other hand, an inclusion complex in which the linearmolecule pierces the cyclic molecule is dispersed in a mixture solventof DMF/DMSO (dimethylsulfoxide) thereby to obtain a solution. These bothsolutions are mixed, in which the inclusion amount of the cyclicmolecule can be freely controlled by changing a mixing ratio ofDMF/DMSO. The inclusion amount of the cyclic molecule increases as therate of DMF in DMF/DMSO is larger.

The blocking group may be any group which can maintain a condition wherethe linear molecule pierces through the cyclodextrin constituting thecyclic molecule, upon being placed at each of the both end terminals ofthe linear molecule as discussed above.

Such a group is a group having a “bulkiness” or a group having an “ioniccharacter”. Here, “group” means a variety of groups including a moleculegroup and a polymer group.

Examples of the group having the “bulkiness” are a spherical group and aside wall-shaped group.

Additionally, the ionic character of the group having the “ioniccharacter” and the ionic character of the cyclic molecule are mutuallyaffected, for example, repel each other, so as to maintain a conditionwhere the linear molecule pierces through the cyclic molecule.

Concrete examples of such a blocking group are dinitrophenyl groups suchas 2,4-dinitrophenyl group, 3,5-dinitrophenyl group and the like,cyclodextrins, adamantane groups, trityl groups, fluoresceins, pyrenes,and derivatives and modified compounds of these.

The material for a curable solvent-based topcoating material, accordingto the present invention, as discussed above is constituted ofpolyrotaxane having hydrophobic modification group(s), in which theoleophilic polyrotaxane can be typically produced as set forth below.

(1) A step of mixing a cyclic molecule and a linear molecule so that thelinear molecule includes the cyclic molecule with piecing through theopening section of the cyclic molecule, (2) a step of blocking the bothend terminals (the both end terminals of the linear molecule) of anobtained pseudo-polyrotaxane with blocking groups so as to makeadjustment to prevent the cyclic molecule from releasing from a piercingcondition, and (3) a step of modifying hydroxyl group(s) held by thecyclic molecule of an obtained polyrotaxane with hydrophobicmodification group(s).

The hydrophobic modified polyrotaxane can be obtained also by using, asa cyclic molecule, a compound in which hydroxyl group(s) previously heldby the cyclic molecule has been previously modified with hydrophobicmodification groups, at the above-mentioned step (1). In this case, theabove-mentioned step (3) may be omitted.

By such a production method, the material for a curable solvent-basedtopcoating material, excellent in solubility in an organic solvent canbe obtained as discussed above.

The organic solvent is not limited to a particular one. Examples of theorganic solvent are alcohols such as isopropyl alcohol, butyl alcoholand the like, esters such as ethyl acetate, butyl acetate and the like,ketones such as methyl ethyl ketone, methyl isobutyl ketone and thelike, ethers such as diethyl ether, dioxane and the like, andhydrocarbon solvents such as toluene, xylene and the like, in which theoleophilic polyrotaxane exhibits a good solubility in a solvent preparedby mixing two or more kinds of these.

In the present invention, the oleophilic polyrotaxane may be crosslinkedas far as it is soluble in an organic solvent. Such an oleophiliccrosslinked polyrotaxane may be used in place of a non-crosslinkedhydrophilic polyrotaxane or upon being mixed with a non-crosslinkedhydrophilic polyrotaxane.

An example of such an oleophilic crosslinked polyrotaxane is anoleophilic polyrotaxane which is crosslinked with a relatively lowmolecular weight polymer which has typically a molecular weight of aboutseveral thousands.

Additionally, in the present invention, it is preferable from theviewpoint of improving the reactivity of the oleophilic polyrotaxanewith other polymers, that each of all or some of the hydrophobicmodification groups has a functional group.

It is preferable that such a functional group is sterically placedoutside of the cyclodextrin, in which reaction of bonding orcrosslinking of the hydrophobic modified polyrotaxane with polymer canbe readily carried out with this functional group.

Such a functional group may be suitably changed, for example, inaccordance with kinds of solvent to be used in case that no crosslinkingagent is used. However, such a functional group may be suitably changedin accordance with kinds of crosslinking agent in case that crosslinkingagent is used.

Further, in the present invention, concrete examples of the functionalgroup are, for example, hydroxyl group, carboxyl group, amino group,epoxy group, isocyanate group, thiol group, aldehyde group and the like,in which the functional group is not limited to these.

In the hydrophobic modified polyrotaxane, the above-mentioned functionalgroup may be used singly with one kind thereof or in combination of notless than two kinds thereof.

Such functional group is particularly a residue group of a compoundcombined with the hydroxyl groups of the cyclodextrin, and the residuegroup preferably has hydroxyl group, carboxyl group, amino group, epoxygroup and/or isocyanate group, in which hydroxyl group is preferablefrom the viewpoint of variety of reactions.

A compound forming such a functional group is, for example,ε-caprolactone; however, the compound is not limited to this.

For example, the compound forming the functional group may be a polymerif a solubility improving effect of the hydrophobic modifiedpolyrotaxane in the organic solvent is not so lowered, in which thepolymer preferably has a molecular weight of, for example, severalthousands from the viewpoint of solubility.

The above-mentioned functional group is preferably a group which canmake a reaction in a condition where the blocking groups cannot leave asdiscussed after.

Next, a curable solvent-based topcoating material and a solvent-basedtopcoating film according to the present invention will be discussed indetail.

The curable solvent-based topcoating material according to the presentinvention is formed from the above-mentioned material for a curablesolvent-based topcoating material. Additionally, the solvent-basedtopcoating film according to the present invention is formed bysolidifying the curable solvent-based topcoating material.

By this, during formation of the coating film, the hydrophobicmodification groups and other functional groups in the material for acurable solvent-based topcoating material react with coating filmforming components to form a crosslinked polyrotaxane, so that thetopcoating material becomes excellent in marring resistance and chippingresistance. Additionally, crack and the like are difficult to beproduced. Further, the topcoating material is excellent also inweatherability, stain resistance, adhesion and the like.

In general, the crosslinked polyrotaxane means a substance which isformed by crosslinking between single polyrotaxane and other polymers.During formation of the coating film, the crosslinked polyrotaxane isformed by crosslinking between the polyrotaxane constituting thematerial for an above-mentioned curable solvent-based topcoatingmaterial and the coating film forming components (polymers, hardeningagents and the like). This coating film forming components are combinedwith the polyrotaxane through the cyclic molecules of the polyrotaxane.

Hereinafter, the crosslinked polyrotaxane will be discussed.

In FIG. 2, the crosslinked polyrotaxane is conceptually shown.

In the same figure, the crosslinked polyrotaxane 1 has the polymer 3 andthe above-mentioned oleophilic polyrotaxane 5. This polyrotaxane 5 iscombined at crosslinking points 9 with the polymer 3 and the polymer 3′through the cyclic molecules 7.

When a deformation stress in a direction of arrows X-X′ at a (A) sectionin FIG. 2 is loaded to the crosslinked polyrotaxane having such aconfiguration, the crosslinked polyrotaxane 1 can deform as indicated ata (B) section in FIG. 2 thereby absorbing this stress.

In other words, as shown in the (B) section in FIG. 2, the cyclicmolecule is movable along the linear molecule 6 under the pulley effect,and therefore the crosslinked polyrotaxane can absorb theabove-mentioned stress thereinside.

Thus, the crosslinked polyrotaxane has the pulley effect as shown in thefigure and therefore has excellent elasticity, viscoelasticity andmechanical properties as compared with conventional gel-like materials.

Additionally, the oleophilic polyrotaxane as a precursor of thiscrosslinked polyrotaxane is improved in solubility in an organicsolvent, and therefore its crosslinking or the like in the organicsolvent is readily made.

Accordingly, the crosslinked polyrotaxane can be readily obtained undera condition where an organic solvent exists. Particularly, thecrosslinked polyrotaxane can be readily produced by crosslinking theoleophilic polyrotaxane with the coating film forming components whichare soluble in an organic solvent.

Accordingly, the material for a curable solvent-based topcoatingmaterial, according to the present invention is being extended in itsapplication range and applicable, for example, to paints or adhesivesusing a coating film polymer which is soluble in an organic solvent,particularly paints, resin base materials and adhesives for automotivevehicles requiring a car-washing resistance, a scratching resistance, achipping resistance, an impact resistance and a weatherability, and alsoto paints, resin base materials and the like for home electricappliances, in which the excellent pulley effect can be exhibited insuch applications.

From the other viewpoints, the crosslinked polyrotaxane is formed as acomposite of the coating film forming components and the polyrotaxanewithout degrading the physical properties of the coating film formingcomponents which are crosslinking objects of the oleophilicpolyrotaxane.

Accordingly, according to the below-discussed production method of thecrosslinked polyrotaxane, not only a material having both the physicalproperties of the above-mentioned coating film forming components andthe physical properties of the oleophilic polyrotaxane itself can beobtained, but also a coating film having a desired mechanical strengthand the like can be obtained by selecting kinds of polymers.

In case that the crosslinking objects are hydrophobic and theirmolecular weight is not so high, for example, up to about severalthousands, the crosslinked polyrotaxane is soluble in an organicsolvent.

Here, a production method of the crosslinked polyrotaxane will bediscussed.

The crosslinked polyrotaxane can be typically formed by (a) mixing thematerial for a curable solvent-based topcoating material with the othercoating film forming components, (b) physically and/or chemically makingcrosslinking of at least a part of the coating film forming components,and (c) combining the at least a part of the coating film formingcomponents and the oleophilic polyrotaxane through the cyclic molecule(hardening reaction).

The oleophilic polyrotaxane is soluble in an organic solvent, andtherefore the steps (a) to (c) can be smoothly carried out in theorganic solvent. Additionally, these steps can be smoothly carried outby using a hardening agent.

At the steps (b) and (c), a chemical crosslinking is preferably made.For example, this is such that the hydroxyl groups disposed in thecyclic molecules of the oleophilic polyrotaxane as discussed above and apolyisocyanate compound as an example of the coating film formingcomponents react with each other to repeatedly form urethane linkages,thereby obtaining the polyrotaxane. Additionally, the steps (b) and (c)may be carried out at the nearly same time.

The mixing step at the step (a) depends on the coating film formingcomponents and can be carried out without a solvent or in a solvent. Thesolvent can be removed under a heating treatment or the like during thecoating film formation.

Additionally, the above-mentioned oleophilic polyrotaxane is containedpreferably in an amount of 1 to 90% by mass relative to the coating filmforming components (resinous solid content and the like). The oleophilicpolyrotaxane is contained more preferably in an amount of 30 to 90% bymass, and particularly preferably in an amount of 60 to 90% by massrelative to the coating film forming components.

If it is contained in an amount less than 1%, the pulley effect islowered thereby providing such a possibility that the elongationpercentage is lowered. If it is contained in an amount exceeding 90%,the smoothness of the coating film is lowered thereby providing apossibility of degrading its external appearance.

Further, the above-mentioned topcoating material is preferably formed bymixing resinous components, hardening agents, additives, pigments,brightening agents or solvents, or one obtained by freely combiningthese with the material for the topcoating material.

Here, the above-mentioned resinous components are not limited toparticular ones, and the main chain or side chain of them preferably hashydroxyl group, amino group, carboxyl group, epoxy group, vinyl group,thiol group or a photocrosslinking group, or a group relating to anycombination of these.

Examples of the photocrosslinking group are cinnamic acid, coumarin,chalcone, anthracene, styrylpyridine, styrylpyridinium salt andstyrylquinoline salt and the like.

Additionally, not less than two kinds of the resinous components may beused. In this case, it is good that at least one kind resinous componentis combined with the polyrotaxane through the cyclic molecule.

Further, such resinous components may be homopolymer or copolymer. Incase of the copolymer, the copolymer may be constituted of not less thantwo kinds of monomers, and may be any of a block copolymer, analternating copolymer, a random copolymer and a graft copolymer.

Concrete examples of the resinous components are polyvinyl alcohol,polyvinyl pyrrolidone, poly(meth)acrylic acid, cellulose-based resinsuch as carboxylmethyl cellulose, hydroxyethyl cellulose, hydroxypropylcellulose and the like, polyacryl amide, polyethylene oxide,polyethylene glycol, polypropylene glycol, polyvinyl acetal-based resin,polyvinylmethyl ether, polyamine, polyethylene imine, casein, gelatin,starch, and a copolymer of these, polyolefin-based resin such aspolyethylene, polypropylene, and a copolymer resin of these with otherolefin-based monomers, polyester resin, polyvinyl chloride resin,polystyrene-based resin such as polystyrene, acrylonitrile-styrenecopolymer resin or the like, acrylic resin such aspolymethylmethacrylate, (meth)acrylate ester copolymer,acrylonitrile-methyl acrylate copolymer or the like, polycarbonateresin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin,polyvinyl butyral resin and a derivative or a modified compound ofthese, polyisobutylene, polytetrahydrofuran, polyaniline,acrylonitrile-butadiene-styrene copolymer (ABS resin), polyamides suchas Nylon (registered trade mark) and the like, polyimides, polydienessuch as polyisoprene, polybutadiene and the like, polysiloxanes such aspolydimethyl siloxane and the like, polysulfones, polyimines, polyaceticanhydrides, polyureas, polysulfides, polyphosphazenes, polyketones,polyphenylenes, polyhaloolefins, and derivatives of these.

The derivatives preferably have hydroxyl group, amino group, carboxylgroup, epoxy group, vinyl group, thiol group, or the photocrosslinkinggroup, or a group relating to a combination of these.

Concrete examples of the above-mentioned hardening agent are melamineresin, polyisocyanate compound, block isocyanate compound, cyanuricchloride, trimethoyl chloride, terephthaloyl chloride, epichlorohydrin,dibromobenzene, glutaraldehyde, phenylene diisocyanate, tolylenediisocyanate, divinyl sulfone, 1,1′-carbonyl diimidazole, and alkoxysilanes, in which these are used singly with one kind or in combinationof not less than two kinds.

Additionally, as the above-mentioned hardening agent, one having amolecular weight of less than 2000, preferably less than 1000, morepreferably less than 600, furthermore preferably less than 400 may beused.

Concrete examples of the above-mentioned additives to be used are adispersant, an ultraviolet ray absorbing agent, a light stabilizer, asurface conditioning agent, an anti-foaming agent, and the like.

Concrete examples of the pigments to be used are an organic coloringpigment such as an azo-based pigment, a phthalocyanine-based pigment, aperylene-based pigment or the like, and an inorganic coloring pigmentsuch as carbon black, titanium dioxide, red iron oxide or the like.

Concrete examples of the above-mentioned brightening agents to be usedare an aluminum pigment, a mica pigment and the like.

Concrete examples of the above-mentioned solvents to be used are esterssuch as ethyl acetate, butyl acetate, isobutyl acetate and the like,ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethers suchas diethyl ether, dioxane and the like, hydrocarbon solvents such astoluene, xylene, solvesso and the like, and long-chain alcohols high inhydrophobicity, in which two or more kinds of these may be suitablymixed. Additionally, even though each solvent contains a slight amountof a water-like solvent such as water, butyl cellosolve acetate and/orthe like, it may be used if it can be considered to be an organicsolvent as a whole.

Further, the above-mentioned topcoating material can be a gloss paint ora flat paint.

In order to make the flat paint, it is sufficient to add a flattingagent(s) such as silica, plastic beads and/or the like in addition tothe above-mentioned components.

Furthermore, the above-mentioned topcoating material can be used as ageneral clear paint, a general paint for base coat or a general enamelpaint so as to form a clear paint film, a base coat paint film or anenamel paint film.

Concretely, the topcoating material is prepared as an acrylic paint, amelamine-based paint, a urethane-based paint, a polyester-based paintand the like.

Additionally, these may be of one package type or of two package type(for example, urethane resin paint) or the like.

Though not specifically limited, it is preferable that the filmthickness of the above-mentioned clear paint is about 20 to 40 μm; thefilm thickness of the above-mentioned base coat is about 10 to 15 μm;and the above-mentioned enamel paint film is about 20 to 40 μm.

Next, a laminated coating film of the present invention will bediscussed in detail.

The paint film of the present invention is formed on an article to becoated, by successively forming a undercoat paint film, a base coatpaint film on the undercoat paint film, and a clear paint film using theabove-mentioned solvent-based topcoating material.

By this, the laminated coating film is improved in scratch resistanceand chipping resistance.

Typical examples of the above-mentioned article to be coated are avariety of metal materials such as iron, aluminum, copper and the like,a variety of organic materials such as polypropylene, polycarbonate andthe like, and a variety of inorganic materials such as quartz, ceramics(calcium carbide and the like) and the like.

Additionally, as methods for coating these with the solvent-basedtopcoating material on these, known and usual methods can be used.Examples of such known and usual methods are brushing, spaying,electrostatic coating, electrodeposition coating, powder coating,sputtering and the like.

Further, the above-mentioned solvent-based topcoating material is formedinto a paint film typically by heating hardening (baking) treatment.

A whole surface or a partial surface of the article to be coated iscoated with the above-mentioned solvent-based coating material.Additionally, in general, the above-mentioned base coat paint filmincludes a clear layer, and the enamel paint film does not include aclear layer.

Additionally, in the laminated coating film of the present invention, itis preferable from the viewpoint of adhesion, that an undercoat paintfilm is further formed between the article to be coated and the basecoat paint film.

Another laminated film of the present invention is obtained by formingthe enamel paint film using the above-mentioned solvent-based topcoatingmaterial on the article to be coated.

By this, the laminated film is improved in scratch resistance andchipping resistance. Additionally, the laminated coating film becomesgood in smoothness.

Additionally, it is preferable that the undercoat paint film is furtherformed between the article to be coated and the enamel paint film. Atthis time, by causing the undercoat paint film to contain a certainresin and/or the like, it is possible that a crosslinking structure withthe oleophilic polyrotaxane is formed at an interface between theundercoating paint film and the enamel paint film, thereby improvingadhesion and the like.

An example (schematic cross-section) of the laminated coating films ofthe present invention as discussed above is shown in FIGS. 3 and 4.

The laminated coating film shown in FIG. 3 is constituted of a undercoatpaint film layer 10, a base coat paint film 11, and an a clear paintfilm 12 as a curable solvent-based topcoating material of the presentinvention, formed on the base coat paint film. Additionally, thelaminated coating film shown in FIG. 4 is formed by successively formingan undercoat paint film 10 and an enamel paint film 11 as the curablesolvent-based topcoating material of the present invention.

The “laminated coating film” includes a coating film formed by coatingthe article to be coated, with only the solvent-based topcoatingmaterial for the purpose of simplicity of illustration. However, thiscoating film is not limited to a single layer and may be formed of aplurality of layers.

EXAMPLES

Hereinafter, the present invention will be discussed in detail withreference to concrete examples; however, the present invention is notlimited to the examples set forth below.

Example 1 (1) Preparation of PEG-Carboxylic Acid by TEMPO Oxidation ofPEG

Polyethylene glycol (PEG) (molecular weight: 1000) in an amount of 10 g,100 mg of TEMPO (2,2,6,6-tetramethyl-1-piperidinyl-oxy radical) and 1 gof sodium bromide were dissolved in 100 ml of water. An aqueous solutionof commercially available sodium hypochlorite (available chlorineconcentration: 5%) in amount of 5 ml was added and stirred at roomtemperature for 10 minutes. In order to decompose excessive sodiumhypochlorite, ethanol was added to an extent of 5 ml in maximum so as toterminate the reaction.

An extraction using 50 ml of methylene chloride was repeated three timesthereby to extract components other than inorganic salts. Thereafter,methylene chloride was distilled out from the extracted components by anevaporator. Then, the components were dissolved in warm ethanol and thenallowed to stand in a freezer (−4° C.) overnight thereby extracting onlyPEG-carboxylic acid, followed by recovering and drying.

(2) Preparation of Inclusion Complex by Using PEG-Carboxylic Acid andα-CD

The above-mentioned prepared PEG-carboxylic acid in an amount of 3 g and12 g of α-cyclodextrin (α-CD) were respectively dissolved in 50 ml of70° C. warm water and 50 ml of 70° C. warm water which were respectivelyprepared, upon which they were mixed and well stirred, followed by beingallowed to stand in a refrigerator (4° C.) overnight. Then, an inclusioncomplex precipitated in a cream-state was lyophilized and recovered.

(3) Amount Reduction of α-CD and Blocking of the Inclusion Complex UsingAdamantane Amine and Bop Reagent Reaction System

The above-mentioned prepared inclusion complex in an amount of 14 g wasdispersed in a mixture solvent of dimethylformamide/dimethylsulfoxide(DMF/DMSO) (75/25 in volume ratio).

On the one hand, 3 g of benzotirazole-1-yl-oxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP reagent), 1 g of1-hydroxybenzotriazole (HOBt), 1.4 g of adamantane amine and 1.25 ml ofdiisopropylethyl amine were dissolved in this order in 10 ml of DMF atroom temperature. This solution was added to the above-mentionedprepared dispersion solution and quickly shaken to be mixed.

A sample in a slurry state was allowed to stand in a refrigerator (4°C.) overnight. After being allowed to stand overnight, 50 ml of amixture solvent of DMF/methanol (1/1 in volume ratio) was added, andthen it was mixed and centrifuged, followed by discarding a supernatant.Washing with the above-mentioned mixture solvent of DMF/methanol wasrepeated two times, and thereafter washing with 100 ml of methanol wasfurther repeated two times under a similar centrifugation.

An obtained precipitate was dried under a vacuum-drying, and thereafterit was dissolved in 50 ml of DMSO, upon which an obtained transparentsolution was dropped into 700 ml of water thereby precipitatingpolyrotaxane. The precipitated polyrotaxane was recovered by acentrifugation, and then vacuum-dried or lyophilized.

A cycle including dissolving in DMSO, precipitation in water, recoveryand drying, as above-mentioned, was repeated two times, thereby finallyobtaining purified polyrotaxane.

(4) Hydroxylpropylation of Hydroxyl Groups of Cyclodextrin

The above-mentioned prepared polyrotaxane in an amount of 500 mg wasdissolved in 50 ml of 1 mol/l aqueous solution of NaOH, followed byaddition of 3.83 g (66 mmol) of propylene oxide. Then, it was stirredovernight in an atmosphere of argon at room temperature. Then, it wasneutralized with 1 mol/l aqueous solution of HCl, and dialyzed by adialysis tube. Thereafter, it was lyophilized and recovered therebyobtaining a hydrophilic modified polyrotaxane of this Example. Theobtained hydrophilic modified polyrotaxane was identified with ¹H-NMRand GPC thereby confirming that it was a desired polyrotaxane. Here, theinclusion amount of α-CD was 0.06, and the modification degree withhydrophilic modification groups was 0.1.

(5) Hydrophobic Group Modification of Polyrotaxane

To 500 mg of the above-mentioned prepared hydroxylpropylatedpolyrotaxane, 10 ml of ε-caprolactone dried by a molecular sieve wasadded and stirred at the room temperature for 30 minutes so as to beinfiltrated. Then, 0.2 ml of tin 2-ethylhexanoate was added, and then areaction was carried out at 100° C. for 1 hour.

After completion of the reaction, a sample was dissolved in 50 ml oftoluene and dropped into 450 ml of stirred hexane so as to beprecipitated, recovered and dried, thereby obtaining a hydrophobicmodified polyrotaxane of this Example.

The obtained hydrophobic modified polyrotaxane was identified with¹H-NMR and GPC thereby confirming that it was a desired polyrotaxane.Here, the inclusion amount of α-CD was 0.06, and the modification degreewith hydrophobic modification groups was 0.02.

(6) Preparation of Clear Paint

The obtained polyrotaxane was dissolved in toluene to form a 10%solution.

Subsequently, the dissolved polyrotaxane was added under stirring to anacrylic•melamine curable clear paint which was Bell Coat No. 6200GN1 ofNOF Corporation.

(7) Formation of Laminated Coating Film

A cationic electrodeposition paint (the trade name “POWERTOP U600M”: acationic electrodeposition paint produced by NIPPON PAINT CO., LTD.) waselectrodeposition-coated on a zinc phosphate-treated dull steel plate of0.8 mm thickness by 70 mm wide by 150 mm long by so as to form a paintfilm having a dried film thickness of 20 μm, followed by baking at 160°C. for 30 minutes.

Thereafter, a gray undercoat (the trade name: Hi-Epico No. 500) of NOFCorporation was coated on the paint film so as to have a paint filmhaving a thickness of 30 μm and then baked at 140° C. for 30 minutes.

Subsequently, a paint Bell Coat No. 6010 metallic color produced by NOFCorporation was painted to form a paint film having 15 μm thickness, andthen the clear paint containing polyrotaxane was painted in a wet-on-wetmanner to form a paint film of 30 μm thickness, followed by baking at140° C. for 30 minutes.

Example 9 (1) Preparation of PEG-Carboxylic Acid by TEMPO Oxidation ofPEG

Polyethylene glycol (PEG) (molecular weight: 35,000) in an amount of 10g, 100 mg of TEMPO (2,2,6,6-tetramethyl-1-piperidinyl-oxy radical) and 1g of sodium bromide were dissolved in 100 ml of water. An aqueoussolution of commercially available sodium hypochlorite (availablechlorine concentration: 5%) in amount of 5 ml was added and stirred atroom temperature for 10 minutes. In order to decompose excessive sodiumhypochlorite, ethanol was added to an extent of 5 ml in maximum so as toterminate the reaction.

An extraction using 50 ml of methylene chloride was repeated three timesthereby to extract components other than inorganic salts. Thereafter,methylene chloride was distilled out from the extracted components by anevaporator. Then, the components were dissolved in warm ethanol and thenallowed to stand in a freezer (−4° C.) overnight thereby extracting onlyPEG-carboxylic acid, followed by recovering and drying.

(2) Preparation of Inclusion Complex by Using PEG-Carboxylic Acid andα-CD

The above-mentioned prepared PEG-carboxylic acid in an amount of 3 g and12 g of α-cyclodextrin (α-CD) were respectively dissolved in 50 ml of70° C. warm water and 50 ml of 70° C. warm water which were respectivelyprepared, upon which they were mixed and well stirred, followed by beingallowed to stand in a refrigerator (4° C.) overnight. Then, an inclusioncomplex precipitated in a cream-state was lyophilized and recovered.

(3) Blocking of the Inclusion Complex Using Adamantane Amine and BOPReagent Reaction System

BOP reagent in amount of 3 g, 1 g of HOBt, 1.4 g of adamantane amine and1.25 ml of diisopropylethyl amine were dissolved in this order in 10 mlof DMF at room temperature. To this, 14 g of the above-mentionedprepared inclusion complex was added, and quickly shaken to be mixed.

A sample in a slurry state was allowed to stand in a refrigerator (4°C.) overnight. After being allowed to stand overnight, 50 ml of amixture solvent of DMF/methanol (1/1 in volume ratio) was added, andthen it was mixed and centrifuged, followed by discarding a supernatant.Washing with the above-mentioned mixture solvent of DMF/methanol wasrepeated two times, and thereafter washing with 100 ml of methanol wasfurther repeated two times under a similar centrifugation.

An obtained precipitate was dried under a vacuum-drying, and thereafterit was dissolved in 50 ml of DMSO, upon which an obtained transparentsolution was dropped into 700 ml of water thereby precipitatingpolyrotaxane. The precipitated polyrotaxane was recovered by acentrifugation, and then vacuum-dried or lyophilized.

A cycle including dissolving in DMSO, precipitation in water, recoveryand drying, as above-mentioned, was repeated two times, thereby finallyobtaining purified polyrotaxane.

(4) Hydroxylpropylation of Hydroxyl Groups of Cyclodextrin

The above-mentioned prepared polyrotaxane in an amount of 500 mg wasdissolved in 50 ml of 1 mol/l aqueous solution of NaOH, followed byaddition of 3.83 g (66 mmol) of propylene oxide. Then, it was stirredovernight in an atmosphere of argon at room temperature. Then, it wasneutralized with 1 mol/l aqueous solution of HCl, and dialyzed by adialysis tube. Thereafter, it was lyophilized and recovered.

(5) Hydrophobic Group Modification of Polyrotaxane

To 500 mg of the above-mentioned prepared hydroxylpropylatedpolyrotaxane, 10 ml of ε-caprolactone dried by a molecular sieve wasadded and stirred at the room temperature for 30 minutes so as to beinfiltrated. Then, 0.2 ml of tin 2-ethylhexanoate was added, and then areaction was carried out at 100° C. for 1 hour.

After completion of the reaction, a sample was dissolved in 50 ml oftoluene and dropped into 450 ml of stirred hexane so as to beprecipitated, recovered and dried, thereby obtaining a hydrophobicmodified polyrotaxane of this Example.

The obtained hydrophobic modified polyrotaxane was identified with¹H-NMR and GPC thereby confirming that it was a desired polyrotaxane.Here, the inclusion amount of α-CD was 0.61, and the modification degreewith hydrophobic modification groups was 0.02.

(6) Preparation of Colored Topcoating Material (Enamel)

The obtained polyrotaxane was dissolved in toluene to form a 10%solution.

Subsequently, the dissolved polyrotaxane was added under stirring to anacrylic melamine curable enamel paint (black paint color) which was BellCoat No. 6010 produced NOF Corporation.

Comparative Example 6 (1) Preparation of PEG-Carboxylic Acid by TEMPOOxidation of PEG

Polyethylene glycol (PEG) (molecular weight: 5000) in an amount of 10 g,100 mg of TEMPO (2,2,6,6-tetramethyl-1-piperidinyl-oxy radical) and 1 gof sodium bromide were dissolved in 100 ml of water. An aqueous solutionof commercially available sodium hypochlorite (available chlorineconcentration: 5%) in amount of 5 ml was added and stirred at roomtemperature for 10 minutes. In order to decompose excessive sodiumhypochlorite, ethanol was added to an extent of 5 ml in maximum so as toterminate the reaction.

An extraction using 50 ml of methylene chloride was repeated three timesthereby to extract components other than inorganic salts. Thereafter,methylene chloride was distilled out from the extracted components by anevaporator. Then, the components were dissolved in warm ethanol and thenallowed to stand in a freezer (−4° C.) overnight thereby extracting onlyPEG-carboxylic acid, followed by recovering and drying.

(2) Preparation of Inclusion Complex by Using PEG-Carboxylic Acid andα-CD

The above-mentioned prepared PEG-carboxylic acid in an amount of 3 g and12 g of α-cyclodextrin (α-CD) were respectively dissolved in 50 ml of70° C. warm water and 50 ml of 70° C. warm water which were respectivelyprepared, upon which they were mixed and well stirred, followed by beingallowed to stand in a refrigerator (4° C.) overnight. Then, an inclusioncomplex precipitated in a cream-state was lyophilized and recovered.

(3) Amount Reduction of α-CD and Blocking of the Inclusion Complex UsingAdamantane Amine and BOP Reagent Reaction System

The above-mentioned prepared inclusion complex in an amount of 14 g wasdispersed in a mixture solvent of dimethylformamide/dimethylsulfoxide(DMF/DMSO) (75/25 in volume ratio).

On the one hand, 3 g of benzotirazole-1-yl-oxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP reagent), 1 g of1-hydroxybenzotriazole (HOBt), 1.4 g of adamantane amine and 1.25 ml ofdiisopropylethyl amine were dissolved in this order in 10 ml of DMF atroom temperature. This solution was added to the above-mentionedprepared dispersion solution and quickly shaken to be mixed.

A sample in a slurry state was allowed to stand in a refrigerator (4°C.) overnight. After being allowed to stand overnight, 50 ml of amixture solvent of DMF/methanol (1/1 in volume ratio) was added, andthen it was mixed and centrifuged, followed by discarding a supernatant.Washing with the above-mentioned mixture solvent of DMF/methanol wasrepeated two times, and thereafter washing with 100 ml of methanol wasfurther repeated two times under a similar centrifugation.

An obtained precipitate was dried under a vacuum-drying, and thereafterit was dissolved in 50 ml of DMSO, upon which an obtained transparentsolution was dropped into 700 ml of water thereby precipitatingpolyrotaxane. The precipitated polyrotaxane was recovered by acentrifugation, and then vacuum-dried or lyophilized.

A cycle including dissolving in DMSO, precipitation in water, recoveryand drying, as above-mentioned, was repeated two times, thereby finallyobtaining a purified polyrotaxane.

(4) Hydroxylpropylation of Hydroxyl Groups of Cyclodextrin

The above-mentioned prepared polyrotaxane in an amount of 500 mg wasdissolved in 50 ml of 1 mol/l aqueous solution of NaOH, followed byaddition of 3.83 g (66 mmol) of propylene oxide. Then, it was stirredovernight in an atmosphere of argon at room temperature. Then, it wasneutralized with 1 mol/l aqueous solution of HCl, and dialyzed by adialysis tube. Thereafter, it was lyophilized and recovered therebyobtaining a hydrophilic modified polyrotaxane of this Example. Theobtained hydrophilic modified polyrotaxane was identified with ¹H-NMRand GPC thereby confirming that it was a desired polyrotaxane. Here, theinclusion amount of α-CD was 0.06, and the modification degree withhydrophilic modification groups was 0.1.

(5) Preparation of Clear Paint

The obtained polyrotaxane was dissolved in toluene to form a 10%solution.

Subsequently, the dissolved polyrotaxane was added under stirring to anacrylic melamine curable clear paint which was Bell Coat No. 6200GN1produced by NOF Corporation.

(6) Formation of Laminated Coating Film

A cationic electrodeposition paint (the trade name “POWERTOP U600M”: acationic electrodeposition paint produced by NIPPON PAINT CO., LTD.) waselectrodeposition-coated on a zinc phosphate-treated dull steel plate of0.8 mm thickness by 70 mm wide by 150 mm long by so as to form a paintfilm having a dried film thickness of 20 μm, followed by baking at 160°C. for 30 minutes.

Thereafter, a gray undercoat (the trade name: Hi-Epico No. 500) of NOFCorporation was coated on the paint film so as to have a paint filmhaving a thickness of 30 μm and then baked at 140° C. for 30 minutes.

Subsequently, a paint Bell Coat No. 6010 metallic color produced NOFCorporation was painted to form a paint film having 15 μm thickness, andthen the clear paint containing polyrotaxane was painted in a wet-on-wetmanner to form a paint film of 30 μm thickness, followed by baking at140° C. for 30 minutes.

Examples 2 to 8, and 10 to 14, and Comparative Examples 1 to 5

Operations similar to those of Example 1 were repeated except forspecifications as shown in Table 1, thereby to form a laminated coatingfilm.

Evaluations (1) to (6) set forth below were carried out on the obtainedlaminated coating films.

(1) Solubility

The colored topcoating material obtained at the step 2 was mixed withit, and then application was made on a glass plate, upon which thecloudiness was evaluated with the eye.

◯: Transparent

Δ: Slightly cloudy

x: Cloudy and separated

(2) Smoothness

The smoothness degree of the topcoating paint film in the laminatedcoating film obtained at the step 3 was evaluated with the eye.

◯: Considerably smooth

Δ: Slightly uneven

x: Uneven

(3) Marring Resistance

A dust flannel (friction cloth) was fixed to a sliding member of anabrasion testing machine with an adhesive tape. Then, the dust flannelwas reciprocated 50 times on the topcoating paint film obtained at thestep 3 under a load of 0.22 g/cm². Then, presence or absence of scratchformed was evaluated.

◯: Nearly no scratch formed

Δ: Slight scratch formed

x: Much scratches formed so as to be conspicuous

(4) Sedimentation of Pigment

The colored topcoating material obtained at the step 2 was allowed tostand in a thermostatic chamber at 40° C. for one month. Then, ajudgment was made as to whether a deposit became a hard cake (solidifiedand in a condition not to be recovered) or not.

◯: Recovered

Δ: Recovered though a time was required

x: Not recovered

(5) Reactivity

The polyrotaxane obtained at the step 1 was mixed with hexamethylenediisocyanate in an equivalent ratio, and then baked and dried at 140° C.for 30 minutes. A judgment was made as to whether urethane linkage waspresent or absent upon measuring an infrared ray absorption spectrum.

◯: Urethane linkage present

x: Urethane linkage absent

(6) Weatherability

A test was carried out for 1440 hours on the topcoating paint film inthe laminated coating film obtained at the step 3 by using a xenonweathrometer (XWOM). Then, measurement of a color difference (ΔE) wasmade.

◯: ΔE≦5

Δ: 3<ΔE≦5

x: ΔE>5

TABLE 1 Polyrotaxane Modification degree Molecular Inclusion withhydrophobic Content (%) Items weight of PEG amount of α-CD modificationgroup in paint film Example 1 1,000 0.06 0.02 50 Example 2 1,000 0.610.02 50 Example 3 45,000 0.06 0.02 50 Example 4 45,000 0.61 0.02 50Example 5 35,000 0.61 0.02 1 Example 6 35,000 0.61 0.02 50 Example 735,000 0.61 0.02 50 Example 8 35,000 0.61 0.02 90 Example 9 35,000 0.610.02 1 Example 10 35,000 0.61 0.02 50 Example 11 35,000 0.61 0.5 50Example 12 35,000 0.61 0.02 90 Example 13 500 0.61 0.5 50 Example 14100,000 0.61 0.5 50 Comparative 35,000 0.61 0.02 0 example 1 Comparative500 0.06 0 50 example 2 Comparative 500 0.61 0 50 example 3 Comparative100,000 0.06 0 50 example 4 Comparative 100,000 0.61 0 50 example 5Comparative 100,000 0.61 0.1 50 example 6 (hydrophilic group) Coatingmaterial Paint film performance Solubility Sedimentation MarringWeather- Items Paint kind to paint of pigment Reactivity Smoothnessresistance ability Example 1 Clear paint ◯ — ◯ ◯ Δ ◯ Example 2 Clearpaint ◯ — ◯ ◯ Δ ◯ Example 3 Clear paint ◯ — ◯ ◯ ◯ ◯ Example 4 Clearpaint ◯ — ◯ ◯ ◯ ◯ Example 5 Clear paint ◯ — ◯ ◯ Δ ◯ Example 6 Clearpaint ◯ — ◯ ◯ ◯ ◯ Example 7 Clear paint ◯ — ◯ ◯ ◯ ◯ Example 8 Clearpaint ◯ — ◯ ◯ ◯ ◯ Example 9 Enamel paint ◯ ◯ ◯ ◯ Δ ◯ Example 10 Enamelpaint ◯ ◯ ◯ ◯ ◯ ◯ Example 11 Enamel paint ◯ ◯ ◯ ◯ ◯ ◯ Example 12 Enamelpaint ◯ ◯ ◯ ◯ ◯ ◯ Example 13 Clear paint Δ — ◯ ◯ Δ ◯ Example 14 Clearpaint Δ — ◯ Δ Δ Δ Comparative Clear paint — — — ◯ X ◯ example 1Comparative Clear paint X — X X X ◯ example 2 Comparative Clear paint X— X X X ◯ example 3 Comparative Clear paint X — X X X Δ example 4Comparative Clear paint X — X X X Δ example 5 Comparative Clear paint X— ◯ X X Δ example 6

As apparent from results of Table 1, it was confirmed not only that thecurable solvent-based topcoating materials of Examples 1 to 14 accordingto the present invention exhibited a good solubility owing to thehydrophobicity of polyrotaxane while exhibiting an excellentsedimentation resistance of pigment, but also that a marring resistancewas improved depending on the pulley effect of the above-mentionedpolyrotaxane while exhibiting good appearance and weatherability.

Regarding Examples 13 and 14, the molecular weight of the linearmolecule is outside a preferable range, and therefore it was confirmedthat there is a tendency that some performances were slightly inferior;however, they were judged to be within a usable level as a whole.

It was revealed that marring resistance, solubility and smoothness ofpaint film were inferior in Comparative Example 1 in which nopolyrotaxane was contained, and in Comparative Examples 2 to 6 usingnon-hydrophilic polyrotaxane whose α-CD (cyclodextrin) was non-modifiedor modified with hydrophilic modification groups.

As discussed above, according to the present invention, an objectiveappearance can be obtained in the same operational efficiency as inusual coatings while making it possible to improve the scratchresistance of the colored topcoating paint film.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 A schematic illustration conceptually showing a hydrophobicmodified polyrotaxane.

FIG. 2 A schematic illustration conceptually showing a crosslinkedpolyrotaxane

FIG. 3 A schematic sectional view showing a structural example of alaminated coating film of the present invention.

FIG. 4 A schematic sectional view showing another structural example ofthe laminated coating film of the present invention.

EXPLANATION OF REFERENCE NUMERALS

1 crosslinked polyrotaxane 3, 3′ polymer 5 hydrophobic modifiedpolyrotaxane 6 linear molecule 7 cyclic molecule (cyclodextrin) 8blocking group 9 crosslinking point 10 undercoating paint film 11 enamelpaint film

1. A curable solvent-based coating material, characterized by comprisingan oleophilic polyrotaxane and a resin, the oleophilic polyrotaxaneincluding a cyclic molecule, a linear molecule piercing through thecyclic molecule, and blocking groups which are placed at both endterminals of the linear molecule to prevent the cyclic molecule fromleaving from the linear molecule, at least one of the liner molecule andthe cyclic molecule having a hydrophobic modification group which is atleast one selected from the group consisting of alkyl group, benzylgroup, benzene derivative-containing group, acyl group, silyl group,trityl group, tosyl group, urethane linkage, ester linkage, etherlinkage and caprolactone.
 2. A curable solvent-based coating material asclaimed in claim 1, wherein the hydrophobic modification group includes(—CO(CH₂)₅OH) group.
 3. A curable solvent-based coating material asclaimed in claim 1, wherein the hydrophobic modification group includes(—CO(CH₂)₅OH) group linked to (—O—C₃H₆—O—) group.
 4. A curablesolvent-based coating material as claimed in claim 1, wherein the cyclicmolecule has an inclusion amount ranging from 0.06 to 0.61 relative to 1which is the maximum inclusion amount of the cyclic molecule capable ofbeing included by the linear molecule.
 5. A curable solvent-basedcoating material as claimed in claim 1, wherein the linear molecule hasa molecular weight ranging from 1,000 to 45,000.
 6. A curablesolvent-based coating material as claimed in claim 1, wherein the linearmolecule is at least one of polyethylene glycol and polycaprolactone. 7.A curable solvent-based coating material as claimed in claim 1, whereinthe cyclic molecule is at least one selected from the group consistingof α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin.
 8. A curablesolvent-based coating material as claimed in claim 7, wherein hydroxylgroups of the cyclodextrin are modified in a modification degree of notless than 0.02 relative to 1 which is the maximum number of the hydroxylgroups of the cyclodextrin which hydroxyl groups are capable of beingmodified.
 9. A curable solvent-based coating material as claimed inclaim 1, wherein the oleophilic polyrotaxane is contained in an amountof 1 to 90% by mass relative to coating film forming components.
 10. Acurable solvent-based coating material as claimed in claim 1, whereinthe coating material is mixed with at least one selected from the groupconsisting of a resinous component, a hardening agent, an additive, apigment, a brightening agent, and a solvent.
 11. A curable solvent-basedcoating material as claimed in claim 1, wherein the curablesolvent-based coating material is one of a gloss paint and a flat paint.12. A curable solvent-based coating material as claimed in claim 1,wherein the curable solvent-based coating material is one of a clearpaint, a base coat paint, and an enamel paint.
 13. A solvent-basedcoating paint film, characterized by being formed by solidifying acurable solvent-based coating material as claimed in claim
 1. 14. Alaminated coating film using the solvent-based coating material asclaimed in claim 1, wherein a base coat paint film and a clear paintfilm using the solvent-based coating material are successively formed onan article to be coated.
 15. A laminated coating film as claimed inclaim 14, wherein an undercoat paint film is further formed between thearticle to be coated and the base coat paint film.
 16. A laminatedcoating film using the solvent-based coating material as darned in claim1, wherein a base coat paint film using the solvent-based coatingmaterial and a clear paint film are successively formed on an article tobe coated.
 17. A laminated coating film as claimed in claim 16, whereinan undercoat paint film is further formed between the article to becoated and the base coat paint film.
 18. A laminated coating film usingthe solvent-based coating material as claimed in claim 1, wherein anenamel paint film using the solvent-based coating material is formed onan article to be coated.
 19. A laminated coating film as claimed inclaim 18, wherein an undercoat paint film is further formed between thearticle to be coated and the enamel paint film.
 20. A laminated coatingfilm using the solvent-based coating material as claimed in claim 1,wherein a base coat paint film using the solvent-based coating materialand a clear paint film using the solvent-based coating material aresuccessively formed on an article to be coated.
 21. A laminated coatingfilm as claimed in claim 20, wherein an undercoat paint film is furtherformed between the article to be coated and the base coat paint film.